The present invention relates to machines for roughing the cement margin of a shoe or other footwear upper assembly.
By way of background attention is called to U.S. Pat. Nos. 3,843,985 (Leondhardt); 3,975,932 (Vornberger); 4,020,660 (Bergeron); 4,090,378 (Sommer); and 4,167,103 (Becka); each of which discloses a roughing machine for roughing the margin of a shoe or other footwear assembly.
In the course of shoe making a shoe (or other footwear) upper is mounted upon a last having an insole upon its bottom, the upper margin being draped over the last and stretched in the manner shown in the U.S. Pat. No. 4,391,012 (Becka), for example; an adhesive is thereafter applied to the margin of the upper which is then wiped to secure the margin to the bottom of the insole to form a footwear upper assembly. Later the margin of the upper assembly is roughed, mostly manually even now, for later application of an outer sole. The patents listed in the previous paragraph and others represent efforts in the shoe machinery industry to provide roughing machines that emulate the manual roughing operation, and do it better and more economically; however the change from manual to automatic is very difficult.
The bottom of a shoe upper assembly in plan view is irregular and characterized by a number of rather abrupt changes in shape. Also, the shoe assembly bottom typically is not planar, nor is there uniformity of contour gradient laterally from the edge of the insole inwardly toward its longitudinal axis (i.e., the crown). In addition shoe bottoms have abrupt longitudinal contour gradients from toe to heel. Any automatic roughing machine must follow those contour gradients while nevertheless achieving roughing of the cement margin in an expeditious fashion. Furthermore, roughing of the margin only must be accomplished, since any slippage onto the side of the upper will ruin the shoe, except those that require side roughing.
Accordingly, it is an objective of the present invention to provide a machine for automatically roughing (i.e., a roughing machine) the cement margin of a footwear upper assembly to remove therefrom the smooth outer surface of leather or synthetic material and thereby enhance bonding of the footwear assembly to an outer sole.
Another objective is to provide a roughing machine that addresses the problems above.
Another objective is to provide a roughing machine that performs the roughing function quickly, effectively and accurately.
Still another objective is to provide a roughing machine whose mechanical structures can be interfaced with the fast-developing electronic devices.
These and still further objectives are addressed hereinafter.
The foregoing objectives are achieved, generally, in a machine for automatically roughing the cement margin of a footwear upper assembly, that includes a support to receive the footwear upper assembly, which ssupport is capable of rocking movement, translational movement and rotational movement; drive means connected to drive the support to achieve the rocking movement, translational movement and rotational movement of the support; a roughing tool mounted to move relative to the footwear upper assembly and operable to achieve roughing of the cement margin as the cement margin moves relative to the roughing tool in the course of the rocking movement, translational movement and rotational movement; and sensing means to provide feedback signals to control the drive means which, on the basis of the feedback signals, acts to maintain a determined orientation between the roughing tool and the footwear upper assembly in the course of relative motion between the two.